Definitions. As used in this chapter, the following
terms shall have the meaning indicated:
AMBIENT NOISE LEVEL
An average of the sound levels associated with a given environment
during a specific time period. As referenced herein, the ambient noise
level is defined to be the A-weighted sound level exceeded 90% of
the time during a representative fifteen-minute period, if such level
is determined. In the absence of such a determination, the ambient
is defined to be 40 dBA.
CYCLICALLY VARYING NOISE
Fluctuating or impulsive noise which varies in sound level
such that the sound level is repeatedly obtained at reasonably uniform
periods of time.
DECIBEL
Logarithmic unit of measure used in describing the amplitude
of sound. Decibel is denoted as dB.
DEVICE
Any mechanism which is intended to produce, or which actually
produces noise when operated or handled.
EMERGENCY VEHICLE
A motor vehicle used in response to a public calamity or
to protect persons or property from imminent danger.
EMERGENCY WORK
Work made necessary to restore property to a safe condition;
work to restore public utilities; or work required to protect persons
or property from an imminent exposure to danger.
FLUCTUATING NOISE
Any noise having a sound level which varies more than six
dBA during a one-minute interval and does not equal the previously
existing ambient noise level more than once during a one-minute interval.
IMPULSIVE NOISE
A noise characterized by excursions of sound levels whose
peak levels exceed the ambient by 10 dBA. The duration of a single
impulse is less than one second.
MOTOR VEHICLE
As defined in the motor vehicle code of the state; or any
vehicle which is propelled or drawn by mechanical equipment.
NOISE DISTURBANCE
Any sound which annoys or disturbs reasonable persons with
normal sensibilities; or any sound which injures or endangers the
health, hearing or safety of others.
PERSON
Any individual, association, partnership or corporation and
includes any officer, employee, department, agency or instrumentality
of the United States, a state or any political subdivision of that
state.
PROPERTY BOUNDARY
An imaginary line at the ground surface, and its vertical
extension, which separates the property owned by one person from that
owned by another person.
REPETITIVE IMPULSIVE NOISE
Any impulsive noise having a sound level which exceeds the
ambient by more than 10 dBA more frequently than once per minute.
RMS SOUND PRESSURE
The square root of the time averaged square of the sound
pressure, denoted "PRMS."
SOUND
A temporal and spatial oscillation in air pressure.
SOUND LEVEL
The weighted sound pressure level obtained by the use of
a sound level meter and frequency-weighting network, such as A, B,
or C, as specified in American National Standards Institute specifications
for sound level meters (ANSI-A1.4-1971, or the latest approved revision
thereof). If the frequency weighting employed is not indicated, the
A-weighting shall apply.
SOUND LEVEL METER
An instrument, including weighting networks, for measuring
sound levels which conform to applicable specifications of the American
National Standards Institute (ANSI) or its successor body.
SOUND PRESSURE
The instantaneous difference between the actual pressure
and the average or barometric pressure at a given point in space.
SOUND PRESSURE LEVEL
Twenty times the logarithm to the base of 10 of the ratio
of the RMS sound pressure to the reference pressures which shall be
0.0002 microbars.